Slow-setting, oil-in-water bituminous emulsion



Patented Oct. 28, 1952 SLOW-SETTING, OIL-IN-WATER BITU- MINOUS EMULSIONDonald N. Manzer, near Walnut Creek, Calif., as-

signor, by mesne assignments, to American Bitumuls & Asphalt Company,San Francisco, 'Calif., a corporation of Delaware No Drawing.

' The present invention relates to bituminous emulsions. 7

When employing a bituminous emulsion, for example an asphaltic emulsion,as a protective or binding material, as in road construction, a constantobject sought in the art is the improvement of the bond between thebitumen of the emulsion and the material to be protected therewith orbound thereto. For example, in the art of constructing and repairing thesurfaces of roads, highways, bridges and the like, it is de: sirablethat the bitumen have a strong amnity for, and strongly adhere to,mineral aggregate. It is further desired that the bituminous substancecoat the individual particles of aggregate thoroughly, uniformly andlastingly, and that the bond between the aggregate and the bituminoussubstance remainunimpaired regardless of weather and condition or typeof aggregate;

For example, in the coating of paving aggregate with a bituminoussubstance, the bond .or the adhesion between bitumen and aggregate inthe presence of water, water vapor and telluric moisture is insecure andweak. As a'result 'of the poor adherence or bond between the aggregateand bitumen, the road breaks down in a comparatively short while, thusincreasing maintenance costs. l

The problem of satisfactorily coating aggregate is "particularlytroublesome when the aggregate is of a hydrophilic nature. Such anaggregate has greater afiinity for water than for the asphalt, as aresult of which water is preferentially adsorbed by the aggregate, thisdisplacing the bitumen and causing the breakdown of the composition..For this reason, locallyoccurring aggregates of a hydrophilic natureoften cannot be employed, and. suitable aggregate far removed from thesiteof construction is re'- quired to be transported to where needed,which procedure adds to the cost of construction.

1 An object of the invention is to provide a bituminous'emulsion such asan asphaltic emulsion capable of adhering more tenaciously to mineralaggregate.

Another object abituminous emulsion exhibiting a stronger bond formineral aggregate, in spite of the deterio rating efiects of thepresence of water.

Still another object of the invention is to pro-' vide a bituminousemulsion satisfactory for use with hydrophilie aggre'gate. s

Yet a further object of the invention is to provide: bituminousemulsionsnot' only characterize'dby superior adhesion properties, butalso by of the'invention is to provide good dehydration and mixingabilityas" herein-f after more fully described.

Application August 14, 1950, Serial No. 179,389

-10 Clain'1s; (Cl. 106-277) ing together of bituminous emulsion and agregate in the presence of an adhesion-promoting salt or mixture of suchsalts selected from the group consisting" of ammonium oxalate, ammoniumformate, ammonium acetate, ammonium glutamate, and ammonium sulfamate,the. said salt or salts being present in an amount sufficient to impartthe improved properties hereinabove described to bitumen-aggregate mix-,tures. As hereinafter shown, the adhesion-promoting salt material'may beadded to'the bituminous emulsion or to the aggregate, or toboth.Preferably, however, the ammonium salt material is incorporated in thebituminous emulsion.

Also in accordance with the invention, it has been discovered that theaforesaid salts are effective with slow-setting bituminous emulsions ofthe oil-in-water type having an aqueous phaseof relatively highalkalinity. Slow-setting bituminous emulsions, prepared in accordancewith the methods hereinbelow described, ordinarily have a pH of about11.5 and higher, as determined by a glass electrode pH meter. Theseemulsions treated with the salts of the present invention have greatlyimproved adhesion characteristics, while bituminous emulsions ofrelatively low alkalinity are not improved to the same extent.

is, those emulsions having a pH of about 11.5

and higher, and not lower than about 9, and preferably not lower thanabout 10. The salts of the present invention have been found'to' be mosteffective when employed in combination with slow-setting. oil-in-waterbituminous emulsions having a-pH within the range of about 9,

preferably -10, to about 11.5 and higher.

It has been found that the foregoing ammonium salts give unpredictableand superiorreammonium salts as ammonium benzoate, ammo- I nium lactate,ammonium salicylate, and ammo-. nium citrate are ineffective to producethe desired degree of adhesiveness necessary to meet specifications, aswill hereinafter appear. Of all the salts of organic acids testedforsuitability, only those specifically enumerated above may satisfactorilybe used. In my copending application, filed August 21, 1951, Serial No.242,989, as a continuation-in-part of my application filed April19,1949, SerialNo, 88,479,n0w abandoned, I describe, and claim certainammonium salts of inorganic acids as suitable adhesion promoting 7 Thus,for best results, it is preferred to. treat emulsions which are highlyalkaline, that agents. In regard to the operability of the suitablesalts enumerated above, it is not known what agent or factor isresponsible in producing the desired results. Thus, such alkali metalsalts as sodium acetate, sodium oxalate, sodium glutamate, etc., areineffective to promote adhesion, indicating that the effectiveness ofthe salt material is not due to the anionicportion of the molecule.Likewise, the cationic ammonium radical is not solely the responsibleagent in producing the desired results, for such saltsas ammoniumbenzoate, ammonium. lactate, etc., a e ineffective for purposes of thepresent invention. It is believed, however, that in order to achieve thedesired effects the combination of theam; monium radical and aparticular organic anion is necessary, the suitability of any unprovenanion as hereinabove indicated being unpredi eb s Y 'Ifhe salts of, thepresent irivention, have been. founds to beuparticularly useiulwhenincorpoe ated, in s ahle or mixing type'bitum nou em la Sims, w i hemu sions, Qrd 'n r lr onta n lil' h g t t r nder t em tab e inst e dowonon act w th l r t s m meralfmatter and the like, Suit femulsions mpledr 'e co daeee wi h, h men i -are.

emulsionsset ontjin- ASTM, Desi 31-46 T ese mul ions, a e-t ei ilizinerg c collo d n ain .e ih r n s le by. v tue h m alsiiying a ent emnlersdtq.- t muls 'fi e tion.

sifihie r i m the u ra .in muls to .De. W9? fitti mulsio t a is.mulsions t i into the to. yts S ine. or when, applied. o. su a es n. heii wmary; anner; may; beprepared convenient,

y he see srta fi s a ts such aszca r o M can, eschews. Su h a nha ts, aras d "wi h, Wa era able alka ne, materi ls w ee h na ura 'qccurrm aci s"to .QT Q. mulsiiyms. agent or agen mo oyed ntheprepr ar tionxof u113M91 m aun... h emul ons. ontempla ed byth ,.v ti v terins'oluble,waters substances; normally .solijd, isern ii-solild; ror viscous q iat. o d na y; atmos he i mne a i ss. T 1 5. --mate a reomers. a n s et oeum,

maze; asphalts, native mineral wages, .as; 60

blownsure, .tars, residual oils, oil gas tar pitch, wood c eretd n o eblemul icmsh a hsl- SiOnI' has been f ormed '-'I5he;. salt may he added1 hose meet n s ecifica ns for.v

.co m ngex edi nt in.nn e r ne steh e mula 7 of soscalledprimary or inqem l l th s abi i ng: asset As is well, knownfinfthe ant 40 br k. q ickup n ntac. h e trov es heltoseni-clw sis. c n ned ha ansl re de r b d;n;i' en-" q i .,613fi 51' to ent emerie nd niPate t:

t r.- la s eeells; es doeai uche sbre eumfa phe s lud e asp alta Pr etc.Of, these materi-als, petroleum. was-l most advantageously used and; it-maxp be, produced" by: steamrrefining, by air blowing,

emulsion ingredients and the salt to conditions of emuls fica ion. as bypa s e mixture through a colloid mill.

The amount 'ofsalt to be incorporated in the emulsion sufficient toimpart to the emulsion an improvement in adhesion meeting specificationsordinarily resides within the range of about 0.3 to 1 ,per cent byweight of the .emulsionrforlmost purposes an amount of salt of about 0.5PEP-0531115.,

and betweenaboutfifi .to 1 per cent being satisfactory.Insomerinstances, amounts asllow. 0.1 per cent and lower may1advantageous1ybe mp oye Insenerat i has, been found. that.

the stronger the alkalinity-oi th e,emulsion, ;.the greater theconcentration of. salt, required .to produce the desired results.

In some instances.,it. may be.desirab1e.to,..treat. the a gr ate. w ththe. salt. -A' regatemar he x dtht e s lt.in rys aliiorm-or.witha-sQ--luti-on thereof care being taken to provide, tor U f is r bu ons-of. thesaltfthroughontnthe ass. of) a ree e.,., he amou t-of. salt. imp es-z d.

being similar to,-' t hat given above, based on. the emulsion.

In order thatstablahituminous emulsions f,u1-

fill their purpose i ciently, it is. desirable that theseemulsionsthave. certain-.properties, such-as go d. ad esion, ighdehydrati n,and ood. m mg abiiltyr Cerlairrtests1.have..aceordinglybeenr devised? to evaluate these properties and.toqsemel as criteria for zthe grading, of the. emulsions.

A useful test,in..-measuring ,the. abilityofma;

bituminous substance. to ,adherafirmly. to ,aggre: e te. 'end.. h 0ne mpoy din.,o.btaining,the.ad= hesion data herein appearingis aslfollows;

00s-samp es QLMfiSSfi-fllllsetts rhy olite, grad. ed, so as,v to, assenti ely. through a ,%.inch :sieve. and to be, ret ined, completely one-,No.. 10, sieve; areheat a 253 1 Q1?-.=1 Ih0HI- o theh atedii samplesthere .is. then. added; 8,,g. of, the; emulsion I being tested. The,.rhyoliteeemulsion samples are mixed, for approximately .zminutes linderinfrared light. until, all stone fragments arercom pletely, coated.,.Arter mixing, the, .samples are.

placed under-infrared.lightatapnroximatly 2005" F. f f or 2," hours;

stirred WithMaUg aS-S, od; for .1 minute atthe rate of R P M. o,f,the.-.rodi.- After-v. stir ine. Water: is drawn off, the sample whichis then- ,--allowed to dry in air. When all thesamplesgaredry they. areexamined usually: by experiencedpb serversto determine. the percentage.orassreeata coated with; asphalt (adhesion); According to this test, a.satisfactorggernulsion WiILgi-y -q hesion. of. not less=than about 1 75,per :cent;;;and

mulsi s meeting; specifi ationss re; rd narily;

required to give such, adhesionvalue,

Stabilized slow-setting, bituminous,.-emulsions At ,the -..end of, this.period, each; sample is remixed for. 1, minute, and 5.0., .,.of each. isplaced .in .400. ml. of. boiling distilledv watercandz jeetionable.drying rates. Such emulsions I are characterized by a' very slowdehydration rate, and when applied as a coating or the like, form a filmor skin on the surface in a manner such that proper drying of theunderlying emulsion is inhibited or prevented. Although emulsions havingthis inferior drying property are useful, it is highly advantageous, andin some instances essential, that :a bituminous emulsion becharacterized not only by stability against breakdown but by theability'to' give off a major portion'of' its contained water in areasonably short time.

A convenient dehydration test, and the one utilized for obtaining thedata given in the present specification on drying rates, is as follows:

100 g. of the emulsion to be testedis placed in a. tared Pyrex dish, '77mm. in inside diameter by 40 mm. in height, having aJflat bottom andtest in 96 hours basedon the loss in a test for residue at 163 C. asdescribed in paragraph 7 To illustrate the practice of the invention,the; following examples are given. It is notintended,- however, to limitthe invention to the examples, since many variations in the preparationand nature of the compositions falling within the scope of the,invention will readily occur to those skilled inthe art.

Example I A primary emulsion was prepared according to the processdisclosed in Montgomerie UJS;

Patent No. 1,643,675 by mixing melted Californiaasphalt of 200-300.penetration with hot, dilute alkaline water. The resulting emulsion wasstabilized by incorporating therein a mixture in water'of caustic soda,the pinewood resin material disclosed in the Walter D. Buckley U. S.

of Tentative Methods, ASTM Designation:

D 244-36T. A satisfactory quick-drying emulsion will show a dehydrationloss of about 60 per cent or more which indicates that the emulsion whenapplied will produce a film of coating which will set and dry uniformlywithout skinning over the surface.

Slow-setting or mixing type bituminous emulsions which are employed forcoating finely graded or dusty aggregates are required to have goodmixing ability, as noted, for example, the

cement mixing test of ASTM Designation:'

D 631-46. These emulsions are required to have stability againstcoalescence or premature breakdown when mixed with aggregate and whenbrought in contact with aggregate, stone or'electrolytes. This stabilityis measured by the cement mixing test described in ASTM Designation: D244-42 (Cement Mixing). The object of this test is the determination ofthe amount of coagulation resulting from mixing Portland cement with theemulsion. In carrying out the test;" g. of Portland cement passingthrough a No. 80 sieve is placed in a round-bottom iron dish.

Then'100 ml. of the emulsion to be tested, diluted to a residue of percent as determined by either distillation or evaporation for 3 hours at16310., is poured on the cement and stirred with a -inch steel rod,making complete revolutions during 1 minute. Atv the end of the 1-minute mixing period, 150 cc.of distilled water is added and stirring iscontinued for 3 minutes. Ingredients and apparatus are maintained at atemperature of approximately 25 C. during mixing-The mixture is thenpoured through atared No. 14 iron sieve and rinsed until the wash wateris clear. Following the washing operation, the. sieve is placed in atarred shallow pan, and heated at a temperature of 163 C. until dry, andthenjweighed; The weight in grams of the material retained on the screenand in the pan is the? percentage emulsion broken. To pass themixingtest 'not more than 2 per cent should be broken.

templated.

Patent No. 2,256,886 (hereinafter referred to as. pinewood resin"), andthe purifiedlignin material disclosed in U. S. Patent No. 2,483,806, toWalter D. Buckley (hereinafter-referred toflas purified lignin"). Therewas then added .to the stabilized emulsion ammonium oxalate in a 20 percent water solution. The finished emulsion contained the followingproportions. of the above-mentioned ingredients by weight. percent:

Primary emulsion 95.125? Purified lignin f 1016001; Pinewood resin 0.250Sodium" hydroxide 0.025" Ammonium oxalate 0430 Water 3.570,

The foregoing emulsion tested as iollowsiv Residue Viscosity, SayboltFurol, 60 m1. at 77F. "36.5 Cement Mixing Pass pH Q T '9.6. Screen (20,mesh) 0.010. Dehydration 0.680,. Adhesion per cent Settlement, 5 days+0.11

The residue, viscosity, screen,'and settlement" tests above listed arestandard tests, description of which may be obtained from ASTMDesignation: D 244-42 under the headings Distillation, V1scos1ty, SieveTest andsettlement, reespectively'.

Other emulsions described in the following examples were preparedsubstantially as described in Example I, that is, from 'a Montgomerietypeprimary emulsion subsequently stablized with an aqueous mixture ofpinewood resin, sodium hy-" droxide, and purified lignin. Afterformation of i the stablized emulsion, the indicated salt was Theexamples that follow illustrate the a heslon'promoting effects p ted toemulsions;

by the incorporation of the salts herein coriemulsion to which rib salthad been added. Into this emulsion there was incorporated instead boricacid to lower the pH of the emulsion and thus render it stable? Astaug'ht in Patent No.' 2,483,806 to Walter D. Buckley, slow-settingemulsions containing purified lignin as astabilizing agent have poorstability unless the pH of the emulsion islowered. When using a salt' ofthe type herein contemplated, no lowering of .--the. pH is. requiredother than that occurring I through'the use'of the s'alt.''I'hu's,'thesalts con- Example 6 represents a control aweto emulsifiedtherein at a pH above about 9 was small amount, sufficient substantiallyto promote adhesion of the emulsified bituminous substance; of at leastone material of the group consisting of ammonium formate, ammoniumacetate, ammoniu n oxalate, ammonium glutamate.

2. The emulsion of claim 1, wherein the" bitu-v minous substance isasphalt.

3. The emulsion of claim 2," wheiin'th S915 Weight of -10 materialisammonium oxalate.

Exegiplc v Example" Example Example Example Ingredients 2 3 I 5 Ammoniumacetate. Ammonium glutauia Ammonium sulfamate.

Boric acid;

I {is indicated by the following analyses, the

foregoing emulsions, except the control emulsion of Example 6. weresatisfactory in all respects, including adhesion. The emulsion ofExample 6 gave an adhesion of only 5 per cent, and was thereforeunsatisfactory.

4. The emulsion of claim 2, wherein the. salt material is ammoniumacetate.

5. The emulsion of claim 2, wherein the salt material is ammoniumglutamate.

6. The emulsion or olaim 2, whereinthe salt material is ammoniumformate.

Example Example Example Example Example 2" 3' f4 5 6 Residue. 58. 57. 8v 58.0 58 0 58. 2 Viscosity '(Saybolt Furol) 87. 2 76. 0 98. 74 8 32Cement test Pass Pass Pass Pass Pass Screen mesh) 0. OlO 0. 025 0. 010Trace 0. 020'- pH 9.2 9.1 9.6 9;7 9.4 Adhesion 95 70 75 85 5 Dehydration715 683 910 625 753 Settlement, 5 day +0. 2 +0; 20 +0. 2 +016 +0. 2

Several other salts were tested for suitability with particularreference to their'abi lity to promote adhesion. The emulsions employedwere substantially the same as those described the examples. The saltammonium lactate was found to give an adhesion of 40 per cent; ammoniumsalicylate, 1 0, per cent; ammonium er D i 12;- em bn u b nzen 5 per cenThe emulsions of the present invention arepart'i'cularlir adaptediormixing with mi eral aggregates in paving and other similar onerationsand compositions; for;- thestabilization of soil mixtureu'seful assurfaces for airports. formak ing. adobe lori-clgs for roads or in darnconstructiohs'end the. lka he moreover, e h b l e a h n P pe i s g oddehy r t o properties and good mixing. ability, while utilizing'relativelyinex pensive salt materials to give results heretofore;incapable of achievement or achieved only throughthezuse-of expensivemate". rials.

. Obviously, many modifications and variations of the invention ashereinbefore set forth. may, be made without, departing from. the spiritand scope thereof, andthereforeonly such limitations,

are tobeimposedas areindic'at'ed in thealbpended. claims.

I claim:

1. A slowsetting. oil-in-yzaterj type emulsion relatively stable againstbreakdownupon. contact with electrolytes consisting essentially ofwater; a water-insoluble, water-dispersibleorganic thermoplasticbituminous substance having been 7. The emulsion of claim I. wherein:the salt material is incorporated thereinto as aiaqueous solution.

8. The emulsion of claim. 1.. whereinathe' salt material is present: inan amount or about."0.3 percent to about. 1 per cent by wei'ght'of theemulsion.

9'. The emulsion of claim 1,, wherein material is Present. in an amountof per cent to about 12 per cent by wei' emulsion.

10. The emulsion of claim. 9, where minous substance, is asphalt and thesalt-material is. ammonium oxalatev DONALD; N. FERENCES; CITED Thefollowing references are" of record the file ofthis patent:-

UNITED? STATES" PATENTS;

France Mar. 1 3',

1. A SLOW-SETTING OIL-IN-WATER TYPE EMULSION RELATIVELY STABLE AGAINST BREAKDOWN UPON CONTACT WITH ELECTROLYTES CONSISTING ESSENTIALLY OF WATER; A WATER-INSOLUBLE, WATER-DISPERSIBLE, ORGANIC THERMOPLASTIC BITUMINOUS SUBSTANCE HAVING BEEN EMULSIFIED THEREIN AT A PH ABOVE ABOUT 9; AND A SMALL AMOUNT, SUFFICIENT SUBSTANTIALLY TO PROMOTE ADHESION OF THE EMULSIFIED BITUMINOUS SUBSTANCE, OF AT LEAST ONE MATERIAL OF THE GROUP CONSISTING OF AMMONIUM FORMATE, AMMONIUM ACETATE, AMMONIUM OXALATE, AMMONIUM GLUTAMATE. 